This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A063508 #3 Mar 30 2012 17:30:32
%S A063508 1,2,4,5,7,13,40,124,758,940
%N A063508 Numbers n such that !n + 2n - 1 is prime.
%t A063508 Do[ If[ PrimeQ[ Sum[ k!, {k, 0, n - 1} ] + 2n - 1 ], Print[ n ] ], {n, 1, 883} ]
%Y A063508 Cf. A063106.
%K A063508 nonn
%O A063508 1,2
%A A063508 _Robert G. Wilson v_, Aug 09 2001